xref: /gem5/src/arch/mips/isa/decoder.isa

// -*- mode:c++ -*-

////////////////////////////////////////////////////////////////////
//
// The actual MIPS32 ISA decoder
// -----------------------------
// The following instructions are specified in the MIPS32 ISA
// Specification. Decoding closely follows the style specified
// in the MIPS32 ISAthe specification document starting with Table
// A-2 (document available @ www.mips.com)
//
//@todo: Distinguish "unknown/future" use insts from "reserved"
// ones
decode OPCODE_HI default Unknown::unknown() {

    // Derived From ... Table A-2 MIPS32 ISA Manual
    0x0: decode OPCODE_LO {

        0x0: decode FUNCTION_HI {
            0x0: decode FUNCTION_LO {
                0x1: decode MOVCI {
                    format BasicOp {
                        0: movf({{ if (xc->readMiscReg(FPCR,0) != CC) Rd = Rs}});
                        1: movt({{ if (xc->readMiscReg(FPCR,0) == CC) Rd = Rs}});
                    }
                }

                format BasicOp {

                    //Table A-3 Note: "1. Specific encodings of the rt, rd, and sa fields
                    //are used to distinguish among the SLL, NOP, SSNOP and EHB functions."

                    0x0: sll({{ Rd = Rt.uw << SA; }});

                    0x2: decode SRL {
                        0: srl({{ Rd = Rt.uw >> SA; }});

                        //Hardcoded assuming 32-bit ISA, probably need parameter here
                        1: rotr({{ Rd = (Rt.uw << (32 - SA)) | (Rt.uw >> SA);}});
                    }

                    0x3: sra({{ Rd = Rt.sw >> SA; }});

                    0x4: sllv({{ Rd = Rt.uw << Rs<4:0>; }});

                    0x6: decode SRLV {
                        0: srlv({{ Rd = Rt.uw >> Rs<4:0>; }});

                        //Hardcoded assuming 32-bit ISA, probably need parameter here
                        1: rotrv({{ Rd = (Rt.uw << (32 - Rs<4:0>)) | (Rt.uw >> Rs<4:0>);}});
                    }

                    0x7: srav({{ Rd = Rt.sw >> Rs<4:0>; }});
                }
            }

            0x1: decode FUNCTION_LO {

                //Table A-3 Note: "Specific encodings of the hint field are used
                //to distinguish JR from JR.HB and JALR from JALR.HB"
                format Jump {
                    0x0: decode HINT {
                        0:jr({{ NNPC = Rs & ~1; }},IsReturn);

                        1:jr_hb({{ NNPC = Rs & ~1; clear_exe_inst_hazards(); }},IsReturn);
                    }

                    0x1: decode HINT {
                        0: jalr({{ NNPC = Rs; }},IsCall,IsReturn);

                        1: jalr_hb({{ NNPC = Rs; clear_exe_inst_hazards();}},IsCall,IsReturn);
                    }
                }

                format BasicOp {
                    0x2: movz({{ if (Rt == 0) Rd = Rs; }});
                    0x3: movn({{ if (Rt != 0) Rd = Rs; }});
                }

                format WarnUnimpl {
                    0x4: syscall();//{{ xc->syscall()}},IsNonSpeculative
                    0x5: break();
                    0x7: sync();
                }
            }

            0x2: decode FUNCTION_LO {
                format BasicOp {
                    0x0: mfhi({{ Rd = xc->readMiscReg(Hi,0); }});
                    0x1: mthi({{ xc->setMiscReg(Hi,0,Rs); }});
                    0x2: mflo({{ Rd = xc->readMiscReg(Lo,0); }});
                    0x3: mtlo({{ xc->setMiscReg(Lo,0,Rs); }});
                }
            }

            0x3: decode FUNCTION_LO {
                format IntOp {
                    0x0: mult({{
                        int64_t temp1 = Rs.sw * Rt.sw;
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                    }});

                    0x1: multu({{
                        int64_t temp1 = Rs.uw * Rt.uw;
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                    }});

                    0x2: div({{
                        xc->setMiscReg(Hi,0,Rs.sw % Rt.sw);
                        xc->setMiscReg(Lo,0,Rs.sw / Rt.sw);
                    }});

                    0x3: divu({{
                        xc->setMiscReg(Hi,0,Rs.uw % Rt.uw);
                        xc->setMiscReg(Lo,0,Rs.uw / Rt.uw);
                    }});
                }
            }

            0x4: decode FUNCTION_LO {
                format IntOp {
                    0x0: add({{  Rd.sw = Rs.sw + Rt.sw;/*Trap on Overflow*/}});
                    0x1: addu({{ Rd.sw = Rs.sw + Rt.sw;}});
                    0x2: sub({{ Rd.sw = Rs.sw - Rt.sw; /*Trap on Overflow*/}});
                    0x3: subu({{ Rd.sw = Rs.sw - Rt.uw;}});
                    0x4: and({{ Rd = Rs & Rt;}});
                    0x5: or({{ Rd = Rs | Rt;}});
                    0x6: xor({{ Rd = Rs ^ Rt;}});
                    0x7: nor({{ Rd = ~(Rs | Rt);}});
                }
            }

            0x5: decode FUNCTION_LO {
                format IntOp{
                    0x2: slt({{  Rd.sw = ( Rs.sw < Rt.sw ) ? 1 : 0}});
                    0x3: sltu({{ Rd.uw = ( Rs.uw < Rt.uw ) ? 1 : 0}});
                }
            }

            0x6: decode FUNCTION_LO {
                format Trap {
                    0x0: tge({{  cond = (Rs.sw >= Rt.sw); }});
                    0x1: tgeu({{ cond = (Rs.uw >= Rt.uw); }});
                    0x2: tlt({{ cond = (Rs.sw < Rt.sw); }});
                    0x3: tltu({{ cond = (Rs.uw >= Rt.uw); }});
                    0x4: teq({{ cond = (Rs.sw == Rt.sw); }});
                    0x6: tne({{ cond = (Rs.sw != Rt.sw); }});
                }
            }
        }

        0x1: decode REGIMM_HI {
            0x0: decode REGIMM_LO {
                format Branch {
                    0x0: bltz({{ cond = (Rs.sw < 0); }});
                    0x1: bgez({{ cond = (Rs.sw >= 0); }});
                }

                format BranchLikely {
                    //MIPS obsolete instructions
                    0x2: bltzl({{ cond = (Rs.sw < 0); }});
                    0x3: bgezl({{ cond = (Rs.sw >= 0); }});
                }
            }

            0x1: decode REGIMM_LO {
                format Trap {
                    0x0: tgei( {{ cond = (Rs.sw >= INTIMM); }});
                    0x1: tgeiu({{ cond = (Rs.uw >= INTIMM); }});
                    0x2: tlti( {{ cond = (Rs.sw < INTIMM); }});
                    0x3: tltiu({{ cond = (Rs.uw < INTIMM); }});
                    0x4: teqi( {{ cond = (Rs.sw == INTIMM);}});
                    0x6: tnei( {{ cond = (Rs.sw != INTIMM);}});
                }
            }

            0x2: decode REGIMM_LO {
                format Branch {
                    0x0: bltzal({{ cond = (Rs.sw < 0); }}, IsCall,IsReturn);
                    0x1: bgezal({{ cond = (Rs.sw >= 0); }}, IsCall,IsReturn);
                }

                format BranchLikely {
                    //Will be removed in future MIPS releases
                    0x2: bltzall({{ cond = (Rs.sw < 0); }}, IsCall, IsReturn);
                    0x3: bgezall({{ cond = (Rs.sw >= 0); }}, IsCall, IsReturn);
                }
            }

            0x3: decode REGIMM_LO {
                format WarnUnimpl {
                    0x7: synci();
                }
            }
        }

        format Jump {
            0x2: j({{ NNPC = (NPC & 0xF0000000) | (JMPTARG << 2);}});

            0x3: jal({{ NNPC = (NPC & 0xF0000000) | (JMPTARG << 2); }},IsCall,IsReturn);
        }

        format Branch {
            0x4: beq({{ cond = (Rs.sw == Rt.sw); }});
            0x5: bne({{ cond = (Rs.sw != Rt.sw); }});
            0x6: blez({{ cond = (Rs.sw <= 0); }});
            0x7: bgtz({{ cond = (Rs.sw > 0); }});
        }
    }

    0x1: decode OPCODE_LO {
        format IntOp {
            0x0: addi({{ Rt.sw = Rs.sw + imm; /*Trap If Overflow*/}});
            0x1: addiu({{ Rt.sw = Rs.sw + imm;}});
            0x2: slti({{ Rt.sw = ( Rs.sw < imm) ? 1 : 0 }});
            0x3: sltiu({{ Rt.sw = ( Rs.sw < imm ) ? 1 : 0 }});
            0x4: andi({{ Rt.sw = Rs.sw & INTIMM;}});
            0x5: ori({{ Rt.sw = Rs.sw | INTIMM;}});
            0x6: xori({{ Rt.sw = Rs.sw ^ INTIMM;}});
            0x7: lui({{ Rt = INTIMM << 16}});
        }
    }

    0x2: decode OPCODE_LO {

        //Table A-11 MIPS32 COP0 Encoding of rs Field
        0x0: decode RS_MSB {
            0x0: decode RS {
                format System {
                    0x0: mfc0({{
                        //uint64_t reg_num = Rd.uw;

                        Rt = xc->readMiscReg(RD,SEL);
                    }});

                    0x4: mtc0({{
                        //uint64_t reg_num = Rd.uw;

                        xc->setMiscReg(RD,SEL,Rt);
                    }});

                    0x8: mftr({{
                        //The contents of the coprocessor 0 register specified by the
                        //combination of rd and sel are loaded into general register
                        //rt. Note that not all coprocessor 0 registers support the
                        //sel field. In those instances, the sel field must be zero.

                        //MT Code Needed Here
                    }});

                    0xC: mttr({{
                        //The contents of the coprocessor 0 register specified by the
                        //combination of rd and sel are loaded into general register
                        //rt. Note that not all coprocessor 0 registers support the
                        //sel field. In those instances, the sel field must be zero.

                        //MT Code Needed Here
                    }});


                    0xA: rdpgpr({{
                        //Accessing Previous Shadow Set Register Number
                        //uint64_t prev = xc->readMiscReg(SRSCtl)/*[PSS]*/;
                        //uint64_t reg_num = Rt.uw;

                        //Rd = xc->regs.IntRegFile[prev];
                       //Rd = xc->shadowIntRegFile[prev][reg_num];
                    }});

                    0xB: decode RD {

                        0x0: decode SC {
                            0x0: dvpe({{
                                int idx;
                                int sel;
                                getMiscRegIdx(MVPControl,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,0);
                            }});

                            0x1: evpe({{
                                int idx;
                                int sel;
                                getMiscRegIdx(MVPControl,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,1);
                            }});
                        }

                        0x1: decode SC {
                            0x0: dmt({{
                                int idx;
                                int sel;
                                getMiscRegIdx(VPEControl,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,0);
                            }});

                            0x1: emt({{
                                int idx;
                                int sel;
                                getMiscRegIdx(VPEControl,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,1);
                            }});
                        }

                        0xC: decode SC {
                            0x0: di({{
                                int idx;
                                int sel;
                                getMiscRegIdx(Status,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,0);
                            }});

                            0x1: ei({{
                                int idx;
                                int sel;
                                getMiscRegIdx(Status,idx,sel);
                                Rt.sw = xc->readMiscReg(idx,sel);
                                xc->setMiscReg(idx,sel,1);
                            }});
                        }
                    }

                    0xE: wrpgpr({{
                        //Accessing Previous Shadow Set Register Number
                        //uint64_t prev = xc->readMiscReg(SRSCtl/*[PSS]*/);
                        //uint64_t reg_num = Rd.uw;

                        //xc->regs.IntRegFile[prev];
                        //xc->shadowIntRegFile[prev][reg_num] = Rt;
                    }});
                }
            }

            //Table A-12 MIPS32 COP0 Encoding of Function Field When rs=CO
            0x1: decode FUNCTION {
                format System {
                    0x01: tlbr({{ }});
                    0x02: tlbwi({{ }});
                    0x06: tlbwr({{ }});
                    0x08: tlbp({{ }});
                }

                format WarnUnimpl {
                    0x18: eret();
                    0x1F: deret();
                    0x20: wait();
                }
            }
        }

        //Table A-13 MIPS32 COP1 Encoding of rs Field
        0x1: decode RS_MSB {

            0x0: decode RS_HI {
                0x0: decode RS_LO {
                    format FloatOp {
                        0x0: mfc1({{ /*Rt.uw = Fs.ud<31:0>;*/ }});
                        0x2: cfc1({{ /*Rt.uw = xc->readMiscReg(FPCR[Fs]);*/}});
                        0x3: mfhc1({{ /*Rt.uw = Fs.ud<63:32>*/;}});
                        0x4: mtc1({{ /*Fs = Rt.uw*/}});
                        0x6: ctc1({{ /*xc->setMiscReg(FPCR[Fs],Rt);*/}});
                        0x7: mthc1({{ /*Fs<63:32> = Rt.uw*/}});
                    }
                }

                0x1: decode ND {
                    0x0: decode TF {
                        format Branch {
                            0x0: bc1f({{ cond = (xc->readMiscReg(FPCR,0) == 0); }});
                            0x1: bc1t({{ cond = (xc->readMiscReg(FPCR,0) == 1); }});
                        }
                    }

                    0x1: decode TF {
                        format BranchLikely {
                            0x0: bc1fl({{ cond = (xc->readMiscReg(FPCR,0) == 0); }});
                            0x1: bc1tl({{ cond = (xc->readMiscReg(FPCR,0) == 1); }});
                        }
                    }
                }
            }

            0x1: decode RS_HI {
                0x2: decode RS_LO {

                    //Table A-14 MIPS32 COP1 Encoding of Function Field When rs=S
                    //(( single-word ))
                    0x0: decode RS_HI {
                        0x0: decode RS_LO {
                            format FloatOp {
                                0x0: adds({{ Fd.sf = Fs.sf + Ft.sf;}});
                                0x1: subs({{ Fd.sf = Fs.sf - Ft.sf;}});
                                0x2: muls({{ Fd.sf = Fs.sf * Ft.sf;}});
                                0x3: divs({{ Fd.sf = Fs.sf / Ft.sf;}});
                                0x4: sqrts({{ Fd.sf = sqrt(Fs.sf);}});
                                0x5: abss({{ Fd.sf = fabs(Fs.sf);}});
                                0x6: movs({{ Fd.sf = Fs.sf;}});
                                0x7: negs({{ Fd.sf = -1 * Fs.sf;}});
                            }
                        }

                        0x1: decode RS_LO {
                            //only legal for 64 bit-FP
                            format Float64Op {
                                0x0: round_l_s({{ Fd = convert_and_round(Fs.sf,RND_NEAREST,FP_LONG,FP_SINGLE);}});
                                0x1: trunc_l_s({{ Fd = convert_and_round(Fs.sf,RND_ZERO,FP_LONG,FP_SINGLE);}});
                                0x2: ceil_l_s({{ Fd = convert_and_round(Fs.sf,RND_UP,FP_LONG,FP_SINGLE);}});
                                0x3: floor_l_s({{ Fd = convert_and_round(Fs.sf,RND_DOWN,FP_LONG,FP_SINGLE);}});
                            }

                            format FloatOp {
                                0x4: round_w_s({{ Fd = convert_and_round(Fs.sf,RND_NEAREST,FP_WORD,FP_SINGLE);}});
                                0x5: trunc_w_s({{ Fd = convert_and_round(Fs.sf,RND_ZERO,FP_WORD,FP_SINGLE);}});
                                0x6: ceil_w_s({{  Fd = convert_and_round(Fs.sf,RND_UP,FP_WORD,FP_SINGLE);}});
                                0x7: floor_w_s({{ Fd = convert_and_round(Fs.sf,RND_DOWN,FP_WORD,FP_SINGLE);}});
                            }
                        }

                        0x2: decode RS_LO {
                            0x1: decode MOVCF {
                                format FloatOp {
                                    0x0: movfs({{if (xc->readMiscReg(FPCR,0) != CC) Fd = Fs; }});
                                    0x1: movts({{if (xc->readMiscReg(FPCR,0) == CC) Fd = Fs;}});
                                }
                            }

                            format BasicOp {
                                0x2: movzs({{ if (Rt == 0) Fd = Fs; }});
                                0x3: movns({{ if (Rt != 0) Fd = Fs; }});
                            }

                            format Float64Op {
                                0x5: recips({{ Fd = 1 / Fs; }});
                                0x6: rsqrts({{ Fd = 1 / sqrt((double)Fs.ud);}});
                            }
                        }

                        0x4: decode RS_LO {

                            format FloatOp {
                                0x1: cvt_d_s({{ int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.sf,rnd_mode,FP_DOUBLE,FP_SINGLE);
                                }});

                                0x4: cvt_w_s({{ int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.sf,rnd_mode,FP_WORD,FP_SINGLE);
                                }});
                            }

                            //only legal for 64 bit
                            format Float64Op {
                                0x5: cvt_l_s({{ int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.sf,rnd_mode,FP_LONG,FP_SINGLE);
                                }});

                                0x6: cvt_ps_s({{ /*Fd.df = Fs.df<31:0> | Ft.df<31:0>;*/ }});
                            }
                        }
                    }

                    //Table A-15 MIPS32 COP1 Encoding of Function Field When rs=D
                    0x1: decode RS_HI {
                        0x0: decode RS_LO {
                            format FloatOp {
                                0x0: addd({{ Fd.df = Fs.df + Ft.df;}});
                                0x1: subd({{ Fd.df = Fs.df - Ft.df;}});
                                0x2: muld({{ Fd.df = Fs.df * Ft.df;}});
                                0x3: divd({{ Fd.df = Fs.df / Ft.df;}});
                                0x4: sqrtd({{ Fd.df = sqrt(Fs.df);}});
                                0x5: absd({{ Fd.df = fabs(Fs.df);}});
                                0x6: movd({{ Fd.df = Fs.df;}});
                                0x7: negd({{ Fd.df = -1 * Fs.df;}});
                            }
                        }

                        0x1: decode RS_LO {
                            //only legal for 64 bit
                            format Float64Op {
                                0x0: round_l_d({{ Fd = convert_and_round(Fs.df,RND_NEAREST,FP_LONG,FP_DOUBLE); }});
                                0x1: trunc_l_d({{ Fd = convert_and_round(Fs.df,RND_ZERO,FP_LONG,FP_DOUBLE);}});
                                0x2: ceil_l_d({{ Fd = convert_and_round(Fs.df,RND_UP,FP_LONG,FP_DOUBLE);}});
                                0x3: floor_l_d({{ Fd = convert_and_round(Fs.df,RND_DOWN,FP_LONG,FP_DOUBLE);}});
                            }

                            format FloatOp {
                                0x4: round_w_d({{ Fd = convert_and_round(Fs.df,RND_NEAREST,FP_LONG,FP_DOUBLE); }});
                                0x5: trunc_w_d({{ Fd = convert_and_round(Fs.df,RND_ZERO,FP_LONG,FP_DOUBLE); }});
                                0x6: ceil_w_d({{  Fd = convert_and_round(Fs.df,RND_UP,FP_LONG,FP_DOUBLE); }});
                                0x7: floor_w_d({{ Fd = convert_and_round(Fs.df,RND_DOWN,FP_LONG,FP_DOUBLE); }});
                            }
                        }

                        0x2: decode RS_LO {
                            0x1: decode MOVCF {
                                format FloatOp {
                                    0x0: movfd({{if (xc->readMiscReg(FPCR,0) != CC) Fd.df = Fs.df; }});
                                    0x1: movtd({{if (xc->readMiscReg(FPCR,0) == CC) Fd.df = Fs.df; }});
                                }
                            }

                            format BasicOp {
                                0x2: movzd({{ if (Rt == 0) Fd.df = Fs.df; }});
                                0x3: movnd({{ if (Rt != 0) Fd.df = Fs.df; }});
                            }

                            format Float64Op {
                                0x5: recipd({{ Fd.df = 1 / Fs.df}});
                                0x6: rsqrtd({{ Fd.df = 1 / sqrt(Fs.df) }});
                            }
                        }

                        0x4: decode RS_LO {
                            format FloatOp {
                                0x0: cvt_s_d({{
                                    int rnd_mode = xc->readMiscReg(FCSR,0);
                                    Fd = convert_and_round(Fs.df,rnd_mode,FP_SINGLE,FP_DOUBLE);
                                }});

                                0x4: cvt_w_d({{
                                    int rnd_mode = xc->readMiscReg(FCSR,0);
                                    Fd = convert_and_round(Fs.df,rnd_mode,FP_WORD,FP_DOUBLE);
                                }});
                            }

                            //only legal for 64 bit
                            format Float64Op {
                                0x5: cvt_l_d({{
                                    int rnd_mode = xc->readMiscReg(FCSR,0);
                                    Fd = convert_and_round(Fs.df,rnd_mode,FP_LONG,FP_DOUBLE);
                                }});
                            }
                        }
                    }

                    //Table A-16 MIPS32 COP1 Encoding of Function Field When rs=W
                    0x4: decode FUNCTION {
                        format FloatOp {
                            0x20: cvt_s({{
                                int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.df,rnd_mode,FP_SINGLE,FP_WORD);
                            }});

                            0x21: cvt_d({{
                                int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.df,rnd_mode,FP_DOUBLE,FP_WORD);
                            }});
                        }
                    }

                    //Table A-16 MIPS32 COP1 Encoding of Function Field When rs=L1
                    //Note: "1. Format type L is legal only if 64-bit floating point operations
                    //are enabled."
                    0x5: decode FUNCTION_HI {
                        format FloatOp {
                            0x10: cvt_s_l({{
                                int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.df,rnd_mode,FP_SINGLE,FP_LONG);
                            }});

                            0x11: cvt_d_l({{
                                int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.df,rnd_mode,FP_DOUBLE,FP_LONG);
                            }});
                        }
                    }

                    //Table A-17 MIPS64 COP1 Encoding of Function Field When rs=PS1
                    //Note: "1. Format type PS is legal only if 64-bit floating point operations
                    //are enabled. "
                    0x6: decode RS_HI {
                        0x0: decode RS_LO {
                            format Float64Op {
                                0x0: addps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    Fd.df = Fs.df + Ft.df;
                                }});

                                0x1: subps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    Fd.df = Fs.df - Ft.df;
                                }});

                                0x2: mulps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    Fd.df = Fs.df * Ft.df;
                                }});

                                0x5: absps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    Fd.df = fabs(Fs.df);
                                }});

                                0x6: movps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    //Fd.df = Fs<31:0> |  Ft<31:0>;
                                }});

                                0x7: negps({{ //Must Check for Exception Here... Supposed to Operate on Upper and
                                    //Lower Halves Independently but we take simulator shortcut
                                    Fd.df = -1 * Fs.df;
                                }});
                            }
                        }

                        0x2: decode RS_LO {
                            0x1: decode MOVCF {
                                format Float64Op {
                                    0x0: movfps({{if (xc->readMiscReg(FPCR,0) != CC) Fd = Fs;}});
                                    0x1: movtps({{if (xc->readMiscReg(FPCR,0) == CC) Fd = Fs;}});
                                }
                            }

                            format BasicOp {
                                0x2: movzps({{if (xc->readMiscReg(FPCR,0) != CC) Fd = Fs; }});
                                0x3: movnps({{if (xc->readMiscReg(FPCR,0) == CC) Fd = Fs; }});
                            }

                        }

                        0x4: decode RS_LO {
                            0x0: Float64Op::cvt_s_pu({{
                                int rnd_mode = xc->readMiscReg(FCSR,0);
                                Fd = convert_and_round(Fs.df,rnd_mode,FP_DOUBLE,FP_PS_HI);
                            }});
                        }

                        0x5: decode RS_LO {
                            format Float64Op {
                                0x0: cvt_s_pl({{
                                    int rnd_mode = xc->readMiscReg(FCSR,0);
                                    Fd = convert_and_round(Fs.df,rnd_mode,FP_SINGLE,FP_PS_LO);
                                }});
                                0x4: pll({{ /*Fd.df = Fs<31:0> | Ft<31:0>*/}});
                                0x5: plu({{ /*Fd.df = Fs<31:0> | Ft<63:32>*/}});
                                0x6: pul({{ /*Fd.df = Fs<63:32> | Ft<31:0>*/}});
                                0x7: puu({{ /*Fd.df = Fs<63:32 | Ft<63:32>*/}});
                            }
                        }
                    }
                }
            }
        }

        //Table A-19 MIPS32 COP2 Encoding of rs Field
        0x2: decode RS_MSB {
            0x0: decode RS_HI {
                0x0: decode RS_LO {
                    format WarnUnimpl {
                        0x0: mfc2();
                        0x2: cfc2();
                        0x3: mfhc2();
                        0x4: mtc2();
                        0x6: ctc2();
                        0x7: mftc2();
                    }
                }

                0x1: decode ND {
                    0x0: decode TF {
                        format WarnUnimpl {
                            0x0: bc2f();
                            0x1: bc2t();
                        }
                    }

                    0x1: decode TF {
                        format WarnUnimpl {
                            0x0: bc2fl();
                            0x1: bc2tl();
                        }
                    }
                }
            }
        }

        //Table A-20 MIPS64 COP1X Encoding of Function Field 1
        //Note: "COP1X instructions are legal only if 64-bit floating point
        //operations are enabled."
        0x3: decode FUNCTION_HI {
            0x0: decode FUNCTION_LO {
                format LoadMemory2 {
                    0x0: lwxc1({{ EA = Rs + Rt; }},{{ /*F_t<31:0> = Mem.sf; */}});
                    0x1: ldxc1({{ EA = Rs + Rt; }},{{ /*F_t<63:0> = Mem.df;*/ }});
                    0x5: luxc1({{ //Need to make EA<2:0> = 0
                        EA = Rs + Rt;
                    }},
                {{ /*F_t<31:0> = Mem.df; */}});
                }
            }

            0x1: decode FUNCTION_LO {
                format StoreMemory2 {
                    0x0: swxc1({{ EA = Rs + Rt; }},{{ /*Mem.sf = Ft<31:0>; */}});
                    0x1: sdxc1({{ EA = Rs + Rt; }},{{ /*Mem.df = Ft<63:0> */}});
                    0x5: suxc1({{ //Need to make EA<2:0> = 0
                        EA = Rs + Rt;
                    }},
                {{ /*Mem.df = F_t<63:0>;*/}});
                }

                0x7: WarnUnimpl::prefx();
            }

            format FloatOp {
                0x3: WarnUnimpl::alnv_ps();

                format BasicOp {
                    0x4: decode FUNCTION_LO {
                        0x0: madd_s({{ Fd.sf = (Fs.sf * Fs.sf) + Fr.sf; }});
                        0x1: madd_d({{ Fd.df = (Fs.df * Fs.df) + Fr.df; }});
                        0x6: madd_ps({{
                            //Must Check for Exception Here... Supposed to Operate on Upper and
                            //Lower Halves Independently but we take simulator shortcut
                            Fd.df = (Fs.df * Fs.df) + Fr.df;
                        }});
                    }

                    0x5: decode FUNCTION_LO {
                        0x0: msub_s({{ Fd.sf = (Fs.sf * Fs.sf) - Fr.sf; }});
                        0x1: msub_d({{ Fd.df = (Fs.df * Fs.df) - Fr.df; }});
                        0x6: msub_ps({{
                            //Must Check for Exception Here... Supposed to Operate on Upper and
                            //Lower Halves Independently but we take simulator shortcut
                            Fd.df = (Fs.df * Fs.df) - Fr.df;
                        }});
                    }

                    0x6: decode FUNCTION_LO {
                        0x0: nmadd_s({{ Fd.sf = (-1 * Fs.sf * Fs.sf) - Fr.sf; }});
                        0x1: nmadd_d({{ Fd.df = (-1 * Fs.df * Fs.df) + Fr.df; }});
                        0x6: nmadd_ps({{
                            //Must Check for Exception Here... Supposed to Operate on Upper and
                            //Lower Halves Independently but we take simulator shortcut
                            Fd.df = (-1 * Fs.df * Fs.df) + Fr.df;
                        }});
                    }

                    0x7: decode FUNCTION_LO {
                        0x0: nmsub_s({{ Fd.sf = (-1 * Fs.sf * Fs.sf) - Fr.sf; }});
                        0x1: nmsub_d({{ Fd.df = (-1 * Fs.df * Fs.df) - Fr.df; }});
                        0x6: nmsub_ps({{
                            //Must Check for Exception Here... Supposed to Operate on Upper and
                            //Lower Halves Independently but we take simulator shortcut
                            Fd.df = (-1 * Fs.df * Fs.df) + Fr.df;
                        }});
                    }
                }
            }
        }

        //MIPS obsolete instructions
        format BranchLikely {
            0x4: beql({{ cond = (Rs.sw == 0); }});
            0x5: bnel({{ cond = (Rs.sw != 0); }});
            0x6: blezl({{ cond = (Rs.sw <= 0); }});
            0x7: bgtzl({{ cond = (Rs.sw > 0); }});
        }
    }

    0x3: decode OPCODE_LO default FailUnimpl::reserved() {

        //Table A-5 MIPS32 SPECIAL2 Encoding of Function Field
        0x4: decode FUNCTION_HI {

            0x0: decode FUNCTION_LO {
                format IntOp {
                    0x0: madd({{
                        int64_t temp1 = xc->readMiscReg(Hi,0) << 32 | xc->readMiscReg(Lo,0) >> 32;
                        temp1 = temp1 + (Rs.sw * Rt.sw);
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                            }});

                    0x1: maddu({{
                        int64_t temp1 = xc->readMiscReg(Hi,0) << 32 | xc->readMiscReg(Lo,0) >> 32;
                        temp1 = temp1 + (Rs.uw * Rt.uw);
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                            }});

                    0x2: mul({{ Rd.sw = Rs.sw * Rt.sw; 	}});

                    0x4: msub({{
                        int64_t temp1 = xc->readMiscReg(Hi,0) << 32 | xc->readMiscReg(Lo,0) >> 32;
                        temp1 = temp1 - (Rs.sw * Rt.sw);
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                            }});

                    0x5: msubu({{
                        int64_t temp1 = xc->readMiscReg(Hi,0) << 32 | xc->readMiscReg(Lo,0) >> 32;
                        temp1 = temp1 - (Rs.uw * Rt.uw);
                        xc->setMiscReg(Hi,0,temp1<63:32>);
                        xc->setMiscReg(Lo,0,temp1<31:0>);
                            }});
                }
            }

            0x4: decode FUNCTION_LO {
                format BasicOp {
                    0x0: clz({{
                        /*int cnt = 0;
                        int idx = 0;
                        while ( Rs.uw<idx> != 1) {
                            cnt++;
                            idx--;
                        }

                        Rd.uw = cnt;*/
                    }});

                    0x1: clo({{
                        /*int cnt = 0;
                        int idx = 0;
                        while ( Rs.uw<idx> != 0) {
                            cnt++;
                            idx--;
                        }

                        Rd.uw = cnt;*/
                    }});
                }
            }

            0x7: decode FUNCTION_LO {
                0x7: WarnUnimpl::sdbbp();
            }
        }

        //Table A-6 MIPS32 SPECIAL3 Encoding of Function Field for Release 2 of the Architecture
        0x7: decode FUNCTION_HI {

            0x0: decode FUNCTION_LO {
                format WarnUnimpl {
                    0x1: ext();
                    0x4: ins();
                }
            }

            0x1: decode FUNCTION_LO {
                format WarnUnimpl {
                    0x0: fork();
                    0x1: yield();
                }
            }


            //Table A-10 MIPS32 BSHFL Encoding of sa Field
            0x4: decode SA {

                0x02: WarnUnimpl::wsbh();

                format BasicOp {
                    0x10: seb({{ Rd.sw = /* sext32(Rt<7>,24)  | */ Rt<7:0>}});
                    0x18: seh({{ Rd.sw = /* sext32(Rt<15>,16) | */ Rt<15:0>}});
                }
            }

            0x6: decode FUNCTION_LO {
                0x7: BasicOp::rdhwr({{ /*Rt = xc->hwRegs[RD];*/ }});
            }
        }
    }

    0x4: decode OPCODE_LO default FailUnimpl::reserved() {
        format LoadMemory {
            0x0: lb({{ Rt.sw = Mem.sb; }});
            0x1: lh({{ Rt.sw = Mem.sh; }});
            0x2: lwl({{ Rt.sw = Mem.sw; }});//, WordAlign);
            0x3: lw({{ Rt.sw = Mem.sb; }});
            0x4: lbu({{ Rt.uw = Mem.ub; }});
            0x5: lhu({{ Rt.uw = Mem.uh; }});
            0x6: lwr({{ Rt.uw = Mem.uw; }});//, WordAlign);
        }

        0x7: FailUnimpl::reserved();
    }

    0x5: decode OPCODE_LO default FailUnimpl::reserved() {
        format StoreMemory {
            0x0: sb({{ Mem.ub = Rt<7:0>; }});
            0x1: sh({{ Mem.uh = Rt<15:0>; }});
            0x2: swl({{ Mem.ub = Rt<31:0>; }});//,WordAlign);
            0x3: sw({{ Mem.ub = Rt<31:0>; }});
            0x6: swr({{ Mem.ub = Rt<31:0>; }});//,WordAlign);
        }

        format WarnUnimpl {
            0x7: cache();
        }

    }

    0x6: decode OPCODE_LO default FailUnimpl::reserved() {
        0x0: WarnUnimpl::ll();

        format LoadMemory {
            0x1: lwc1({{ /*F_t<31:0> = Mem.sf; */}});
            0x5: ldc1({{ /*F_t<63:0> = Mem.df; */}});
        }
    }


    0x7: decode OPCODE_LO default FailUnimpl::reserved() {
        0x0: WarnUnimpl::sc();

        format StoreMemory {
            0x1: swc1({{ //Mem.sf = Ft<31:0>; }});
            0x5: sdc1({{ //Mem.df = Ft<63:0>; }});
        }
    }
}